It is well known that since the appearance of the first cases of AIDS, in the early 1980s, we have accumulated dramatic advances in the biomedical, political, social and human rights fields. In spite of the successes in recent decades, the HIV/AIDS epidemic remains a grave public health problem, particularly for poor and marginalized populations in diverse societies. Research indicates that reduced susceptibility to the HIV virus depends on the reach of basic rights of citizenship and fairness of opportunity to diverse social and gender segments. Integral to these considerations are the limitations of preventative politics that focus on epidemiological and behavioral approaches, characterized by an emphasis on education and individual responsibility. In this sense, studies on the relationships between structural factors and sociocultural contexts gain relevance for the meaning of HIV vulnerability. In accord with this perspective, advancements are necessary in the development and availability of structural interventions capable of integrating social, political, economic and cultural spheres in prevention and assistance efforts 1.

The article under consideration by Vlahov & Celentano converges with this discussion when mentioning shifts in focus from individual interventions and peer-to-peer networks to structural interventions in HIV prevention and control efforts for injection drug users (IDUs). According to this approach it is necessary to integrate access activities with treatment and damage reduction programs for drug abusers, including needle exchange, education efforts, counseling and assistance in legal and political spheres. This perspective integrates quality health services, adequate for the particularities of this group, and psycho-social support actions, aiming at the reduction of stigma and social inclusion of users.

If the lessons learned have motivated initiatives to revise efforts to combat the HIV/AIDS epidemic among different social groups, some advances bring new challenges. This means that in addition to old problems, associated with socioeconomic and gender inequalities, there are new emergent problems. One recent question addresses the effects of highly active anti-retroviral therapy (HAART) on the course of the epidemic. Despite its proven benefits, the therapy's positive effects on time and quality of life for carriers of the HIV virus can result in increased chances of transmission if patients do not adopt preventative practices. Besides the risks of transmission of resistant viral strains, the efficacy of treatment can promote relaxation of preventative practices due to the belief that AIDS is rendered chronic by the new therapies. In sum, the positive results obtained can stimulate changes in how people view the epidemic's fatality, capable of reducing preoccupation with HIV prevention. This situation illustrates the relevance of integration of preventative measures with assistance for carriers (or non-carriers) of the virus, aiming at improvements brought by HAART in prognosis, progression and mortality reduction.

The article under discussion, Access to Highly Active Antiretroviral Therapy for Injection Drug Users: Adherence, Resistance, and Death, contributes new and important elements to the discussion of the limitations imposed by IDUs and HAART. In an extensive and up-to-date review of the academic literature, the authors identify issues regarding the degree of effectiveness of HAART within this group as a function of supposed differences in the natural history of HIV, arising from the use of illicit drugs. Other investigations focus on the difficulties for IDUs of access and compliance to the procedures required for this therapy, as well as how the clinical improvements may lead to relaxation of safer preventative practices.

Clearly and consistently argued, this work demonstrates that the diverse studies in this field are variable, incomplete and inconclusive, and that it is pertinent to consider further the use of HAART among IDUs. To this end, they examine how factors attributed to the limits of therapy among IDUs, such as low frequency of healthcare, might be overcome by adapting services to their needs. It adds to this formulation evidence of the value of experience on the part of health professionals for treatment adhesion among this group. The authors also emphasize the benefits of integrating the antiviral therapy regime with drug abuse treatments, as well as the negative implications of preconceptions regarding the incapability of IDUs to adhere to the regiments demanded by HAART, due to their social and psychological characteristics. They reflect on how these problems, to a large degree, are related to the active use of drugs, and that assistance and inclusion in chemical dependency treatment programs positively influence therapeutic adhesion. Given these arguments, Vlahov & Celentano affirm that restrictions on the prescription of HAART for IDUs is not consensual, and access to the benefits of the therapy should not be limited for this population. In their words, "reduced access to medication can not be an a priori condition, for once barriers to access are resolved through various means, treatment should be considered" (p. 711).

The problems of access and of quality of treatment for socially marginalized groups, such as IDUs, remind us of the stigmatizing and alarmist views that have long accompanied the AIDS epidemic. Marked by the division between those blamed for the dissemination of the virus (homosexuals, "deviants", "promiscuous", "junkies", Africans, sex professionals) and defenseless victims (children and homophiles), these perspectives reveal the stigmas associated with gender, race/ethnicity, class and sexuality relationships. Besides promoting discrimination, such perspectives collaborated to disseminate the virus among diverse segments of society, including those "beyond risk". Without doubt there were important fights and some advances with respect to fatalistic and discriminatory perspectives. Nevertheless, prejudices still exist that impede access to health prevention and assistance by marginalized social groups. Evaluations of the effectiveness and potentiality of integrated approaches for prevention and control of HIV including for drug users, mentioned above, reveal the viability of establishing alternatives for segments that live at the margins of society, favoring their social integration. The discussion presented by Vlahov & Celentano thus constitutes an important and opportune consideration of the possibilities in the field of public health for confronting challenges involving stigmatized social groups and illicit activities.

To advance this debate, I believe the authors' argumentation could be furthered by additional social science field investigations, enabling a deeper understanding of the world view and social practices of drug users with respect to health and other aspects of life. In the case of AIDS, the socio-anthropological approach has revealed the diversity of cultural manifestations in modern societies, in terms of variations in identity, gender and social perceptions and practices, thereby contributing to discussions of sexuality in ways that may (re)orient programs for combating the disease. Expanding studies concerning the particularities of the drug user universe may complement broader discussions regarding the adequacy of educational and health assistance strategies.